Eternal Research
by Shadow Labrys
Summary: An old friend of the Lastation Sister's return after a long journey which made them happy, and as usual they won't admit it. Their old friend just so happened to be an immortal mage with incredible knowledge of magic but is incredibly useless in any fight. She holds a big secret and promise from people long gone and she'll fulfil it no matter what. OC x harem.
1. Immortal Mage

In Lastation's Basilicom, Noire, the CPU of Lastation, worked in her office alone late into the night as her sister, Uni, was currently sleeping in her room. Noire let out a bored sigh after she put down her pen while she stared outside towards her balcony. _'I know I just went to Lowee, but I kinda wish the others would maybe visit me a little more.'_ Noire thought as she let out another sigh and just as she was about to get back to work a very familiar small black and blue mage hat float down from nowhere. She looked up in surprise to someone hanging from her ceiling by their foot. "What the!?"

"Hey, Noire! I know that sigh from anywhere. I see you're still pretty lonely, aren't you?"

"Sh-Shut up!" Noire shouted as she heard something start to crumble and realized it was the ceiling that made the noise since it gave away while the girl came screaming and crashing down. Noire stared at the other side of her desk for a few seconds before a staff appeared.

"Repair..." She said as the orb on top of the staff started to glow a light green colour as Noire's ceiling started to repair itself. Soon after that, the girl stuck in the ceiling rose up from the ground adjusting her hat. Under her hat is black short hair that reaches her shoulders and she wore black sunglasses. She wore a black and white, with a light blue accent, mage coat that reaches past her hips and is somewhat big on her. It was buttoned up slightly and a pin of a little black diamond with blue lining and a white horn rested on one side of her collar and a crescent moon pin on the other. Underneath it is a white dress shirt with a black tie. She wore black tights and white mid-calf-high boots with black laces and on her shoulder rested a satchel of the same colour as the rest of her clothes.

"Geez... I see you're back, Luna." Noire said. "How did you ended up there?"

"Yep! I'm back! To answer how I got up there, well, I started to develop a teleportation spell, but I haven't quite perfected it yet as you could see. So what happened while I was gone?"

"Well, since you were gone all four nations signed a peace treaty."

"That's wonderful! Congratulations, Noire!" Luna smiled, and Noire could help the small blush that crept onto her cheeks, but she failed to notice that her smile disappeared. "...I won't have to witness another Nation fall." Luna muttered that last part to herself.

"What was that?"

"Oh, nothing." The door opening behind Luna caught both their attention and they looked to see who it could be at this hour. It ended being a Noire's sister, Uni, who looked pretty annoyed and tired considering she was rubbing her eyes.

"Noire... what's with all the noise? I'm trying to... sleep..." Uni said as she noticed that someone else was with her and it dawned on her who it was. "L-Luna! You're back!"

"Yep! It's great to see you again." Luna held her arms out waiting for Uni to act which she did by running over to her and hugged her the moment she was close enough. "Oh, wow. You must have missed me. I actually didn't expect a hug."

"O-Of course I didn't! I just was really tired and..."

"Haha, you're just like your sister. You can never admit your feelings."

"What does that mean?" Noire said.

"You know what I mean. I could say something as mild as... I like you a lot." Luna said as Noire blushed madly and tried to play it off like she was wrong. "...and you would blush furiously, and the little sister is upset that I said that to you and not her."

Uni gasped a little before quickly looking from Luna who has an amused smile on her face that pretty much said: "I'm right, aren't I?". Uni huffed before she looked over to the two who her sister still was blushing a little bit. She didn't like what she was seeing so she tried to divert her attention. "What are you doing here so late?"

"Oh, yeah. I have found the items that I've been looking for so long." Luna said as she dug around in her satchel and pulled out the items she was talking about which happened to be feathers, three horns of some sorts, and three ominous looking orbs. "I've finally found the legendary Phoenix! And I'm not talking about those dumb robot birds, I'm talking about an actually fiery bird that dies and comes back to life. It sucked too, the moment I found the thing it died on me and I had to wait for it to be reborn and mature before I could get these feathers."

"Really? I didn't think they existed." Noire said as she noticed that smoke was emanating from Luna's hand. "Uh, what's wrong with your hand?"

"Oh, it burns holding these Phoenix feathers, and yes, it's quite painful. I'm just, uh, gonna put these back." Luna said as she put the feathers away and tenderly rubbed her hand. "These are Unicorn horns, and these are the evil cores from powerful monsters."

"What do you need these things for?" Noire asked.

"It's for a spell," Luna answered.

"And what spell would that be? Is it something I should be worried about?"

"No, it's nothing that you have to worry your pretty little head off. Uh... It's purification, I guess."

"Okay."

"Welp, I should get to my research is what I want to say, but I haven't slept in three days," Luna said as she rubbed her eyes tiredly while letting let out a yawn.

"You really need to take care of yourself more," Noire said.

"I don't need to take care of myself. My body is always in perfect condition. Thank you immortality."

"Still, you can't just stop doing that."

"Oh, is Noire actually showing some worry for me? I am honoured. You know what? I'll get some sleep, but I don't exactly have a place to stay."

"Uh, I got a place in mind," Uni said.

"Really?"

"How about here, in the Basilicom?" Uni suggested.

"Really? Can I stay here? You know might cause something to happen because of my research?" Luna said as she turned towards Noire who just happen to let out a little sigh since she heard those words come out of her mouth.

"Well, as long as you can promise not to destroy anything I guess it's fine."

"I only promise to try."

"Alright, fine. You can stay here." Noire said with a sigh once again.

"I can lead you to somewhere you can sleep," Uni said.

"Okay, lead the way," Luna said as she followed Uni out of Noire's office and down the hallway until they stopped in front of a room. The moment the door open Luna knew that this wasn't some guest bedroom since there was stuff like guns hanging on the wall and parts lying on a table. "Isn't this your room? What are you trying to say?" Luna said in a suggestive tone but clearly, that was only meant to mess with her.

"D-Don't get the wrong idea. The other rooms aren't ready for someone to stay in them."

 _'That's a lie, but whatever, I don't care where I sleep as long as I get some sleep.'_ Luna thought as she walked over to the bed as she took off her hat and placed her satchel and staff on the nightstand. She rested her head on the pillow and she let out a content sigh from finally sleeping on something soft for once. Just as she was about to fall asleep she heard the bed rustle a little which only meant that Uni was climbing into the bed. She felt the CPU Candidate arms wrap around her while she rested her head on Luna's shoulder and she opened one eye slightly to see what she was doing.

"...How did I fall for someone like you?" Uni said to herself.

 _'How indeed. I don't really deserve something like this.'_ Luna thought as she closed her eyes. _'At least, not until I save her from herself and fulfil my promise.'_


	2. A Bet

Uni awoke in her room to find the bed empty, she rubbed the tiredness out of her eyes until the sudden realization of what she said last night came back to her. She blushed a little, feeling embarrassed to which she shook her head of those thoughts. She looked around the room to see that Luna's hat and satchel were gone but her staff was still next to the bed. Uni got off the bed before she got ready for the day and headed out to help her sister out with the Nation. She walked down the hallway towards Noire's office and she was about to open the door, she didn't expect to hear a loud bang come from the room. Panicking a little, Uni slammed opened the door and found Noire to be completely safe since she had in her hand in her face in mild annoyance and the source just so happened to be from their recent addition. At the last second, Uni noticed Luna fall from somewhere outside since she landed on their balcony. When they noticed that she wasn't moving they got a little worried and decided to check up on her to make sure she was okay. When they stopped next to her they noticed that she was still at least conscious since she was staring at them. "Don't worry, I'm fine."

"Don't worry? I thought you said I didn't have to worry about your spell?" Noire said.

"That was nothing. It was nothing but a loud bang."

"Yeah, right. You hit the roof because of your spell."

"Maybe so, but nothing is broken is it?"

"N-No."

"See! Nothing is broken, but the same can't be said about my back."

"What?!" Both Uni and Noire shouted in unison.

"W-What do we do?" Uni asked in a slight panic.

"Nothing."

"Nothing?"

"Yep, nothing," Luna said as she stood up shocking the both of them and they watched as she stretched her back while letting out a content sigh. "Ah, that's much better. Is it weird that I look forward to the pain?" The moment she asked, Luna noticed that the Lastation sisters' expression changed from worried to weird out by what she said.

"What do you mean by that?" Noire asked.

"Oh, I guess what I said could be taken as me being a masochist. That's not it at all! I just... whenever I get injured, I get this feeling of bliss whenever my body heals. Hmm... I wonder if that's a side effect of the immortality? It must be because that never happened before I obtained it." Luna started muttering to herself.

"So... does that mean you don't feel pain?" Uni asked.

"Oh no! It's still incredibly painful, unbearably sometimes." Luna said with a small smile while she grabbed her satchel and stood in front of the CPU sisters. "I think I'm done with what I was doing, besides I'm probably annoying you, aren't I, Noire?"

"Just a little."

"Yeah... well, anyway, how's your Nation doing, Noire?"

"Everything is going well. I honestly didn't think your advice would be helpful, but I was wrong."

"That's good. Well, I do know how to improve a Na-, um, town. I've lead people before but don't expect any more advice. What I gave you was, unfortunately, all I had."

"That's a shame."

"Well, I'll see you later, Noire."

"Wait, where are you going?" Noire asked as suddenly Luna grabbed Uni's wrist and led her out of Noire's office but stopped to answer her.

"Oh, I'm just going to spend some time with Uni."

"B-But, I want to... I mean, I got nothing to do so I c-could spend it with... you." Luna started at Noire's nervous face since she wasn't looking at her as she just stared at the wall. Luna knew she was lying about having free time since when she looks over to her desk to see a pile of papers on it.

"You really shouldn't neglect your work. Your Nation will suffer because of it." Luna said.

"Y-You're right."

"Alright, if you're still up to it, I'll hang out with you after you finish your work."

* * *

Uni followed Luna down the hall until they stopped in front of her room and wondered what she could be doing here. She watched as Luna leaned against one of her tables mainly the one where she works on her guns with. "We used to spend a lot of time together, haven't we?"

"Uh, yeah, I guess so."

"All we did was talk about guns and you even taught me how to shot, although, I wasn't really good at it," Luna said as she walked over to the CPU Candidate and made Uni look up a little since she was taller than her. "Why don't we go to the shooting range? I've been practising as much as I could since I left, I think I could beat you this time."

"You really think you could beat me?"

"I don't know, but that uncertainty is what makes this fun. Let's make a bet so that it's more exciting!"

"A bet? What sort of bet?"

"How about the loser does one thing that winner wants. It could be anything."

"Anything?"

"Anything," Luna said as she walked out of the room leaving behind Uni. "Come on! Let's go!"

* * *

In the shooting range, Luna and Uni began their little bet with it obviously ending in Uni's favour since she has more experience than Luna ever has. Out of the entire time they were there, Luna was able to hit the target more but not in the spot she wanted. Though, Uni's was different since every one of her shots hit the mark at almost all did but one. "So... how long have you been into me?" Luna asked just before she fired her last shot.

"W-What?!" Uni shouted as her last shot missed the target. Uni carefully placed her gun down and turned towards Luna but was also trying to hide the blush on her face. "What makes you think I'm into you?"

"Well, with how red your face is right now. Also, what you said last night."

 _'She was still awake?! She was so tired last night I thought she fell asleep already.'_ Uni thought. "I-I don't know what you're talking about. You must have been dreamed it."

"Ah, okay. Yeah, it must have been a dream. Well, that's too bad honestly." Luna said as she leaned a little closer to Uni. "That would have been great if it was real. I'd honestly be interested, but too bad that's just a dream." Luna noticed that Uni was frustrated with herself and the next thing she heard come from Uni's mouth surprised her.

"Fine! I won that bet so that means you have to do one thing for me!"

"Yeah, that's what we agreed to."

"Alright, fine. Then we're going on a d-date you hear me!"

 _'Oh, wow. I never expected her to say that.'_ Luna thought. "You mean like, we hang out and whatnot, or do you mean the romantic type?"

"T-The... romantic kind..." Uni said as she looked away trying to hide her blush.

 _'Okay, I wasn't expecting that. I honestly thought that she would try to backpedal but I guess I was wrong.'_ Luna just simply shrugged before speaking. "Alright, I did agree to that bet since I was the one who made it. I'll leave the planning to you."

"R-Right... I'll...I'll see you tomorrow."


	3. A Date With A Candidate

In Noire's office, Luna sat on one of the couches while she wrote in her journal with clear sharp focus. Noire from her desk glanced from her work and watched as Luna muttered to herself about something. "...I need to adjust how much magic I use so I don't have a repeat of what happened yesterday. Also, maybe if I adjust this and that maybe it'll work this time. I hope it works, it has to work."

 _'She's so serious about this spell.'_ Noire thought, and just as she was about to go back to work she heard Luna close her journal.

"I think it's about time I leave for my date."

"D-Date!?" Noire stood up so fast that she accidentally hit her desk and nearly knocked the piles of papers over. "I...I didn't know you were interested in having a relationship." Noire said as she tried to play off what happened by trying to act a little casual.

"I'm not really looking for one, but I did make a bet with Uni. If she wants to go on a date with me then I'll go on a date with her."

"Wait! Uni!?" Noire shouted in shock.

"It's a surprise, isn't it? I didn't expect that to be what she wanted out of the bet."

"What exactly did you bet on?"

"I just wanted to see who could beat who in the shooting range..."

"And you thought you could beat Uni?"

"I've been practising! I can definitely hit the targets now. Besides, like what I said to Uni that uncertainty about winning makes it more fun and exciting."

"Okay, I guess I understand that."

"I'll see you later, Noire," Luna said as waved before exiting Noire's office.

* * *

Uni nervously paced back and forth in front of the Basilicom, the source of her nervousness just happened to be the person she was going to spend the day with. After she cooled down from yesterday, Uni slowly started to regret what she asked for, mainly for two reasons, one was that she never went on a date before because she was always busy so she didn't even know what to do. Two is, she realized that she basically confessed to having an interest in her and that made her panic a little since she didn't really know if she was or not. Uni knew that she could always ask Luna herself if she legitimately liked her that way, but she knew her long enough that she would either dodge the question or mess with her in some way and would never get a straight answer out of her.

"Boo!"

"Eek!" Uni jumped at the sudden noise from behind her and she looks to see that the source of the belonged to the person she was waiting. Uni quickly composed herself when she noticed the amused smirk on Luna's face.

"Look how nervous you are."

"W-What are you talking about? I'm completely fine."

"Alright sure. Come on. We got a date to go to." Uni nervously nodded as she walked with Luna down the street but unknown to them Noire was secretly watching them. "So, what did you have planned? You know, I am willing to do anything you want."

"A-Anything?" Uni and Noire said, although, it was from her hiding spot.

"Yes, anything. Since this is you we're talking about here, I'm guessing that there's a gun shop you want to go to, or maybe there's some part that you wanted, but was never able to afford."

"Uh, yeah, actually."

"Well then, let's go." Noire followed them down the street wearing only glasses as any sort of a disguise. She followed them until they arrived at a gun store and watched them as they looked at everything while Uni explained what they did.

"Since when does Uni like her? Maybe I should ask too... No! I don't have time for one..." Noire said to herself but before she could go any further she snapped out of it and hid behind a corner since Uni and Luna walked out of the store. Noire peeked out from her corner to see that Uni seemed a little upset for some reason.

"You didn't have to do that."

"Well, I wanted to."

"Why did you buy it anyway?"

"You wanted it, so I thought, I might as well get it for you as thanks."

"Thanks for what?"

"For teaching me about weaponry. It's honestly fun when we do that."

"Yeah, but it was pretty expensive..."

"Don't worry. I've amassed quite the fortune throughout my life."

"I see. Uh, well then, thank you."

"You're welcome." Noire quickly hid from their sight when she noticed Luna look over in her direction.

"What's wrong?" Uni asked.

"Hmm... I thought I saw someone, but I must have been seeing things." Once she heard her say that, Uni looked in the direction she was looking but saw no one. They both just decided to continue onward towards the next place.

"Crap... I almost got caught. I need to be more careful." Noire said.

She followed once again through the streets of Lastation until they arrived at an arcade where they were obviously here for some fun. At first they were playing with each other or taking turns during one of the games, but eventually, they started playing against each other. Though their versus games ended with Luna losing six games in a row which made her let out a frustrated growl and Uni was smirking confidently. "Damn it! I can't win!"

"Better luck next time."

"I will beat you sometime."

* * *

 _ **Two Hours Later**_

The couple ended up in Lastation Park where Noire noticed Uni was acting more strange than before which confused her since she never has seen her little sister act like this. Uni slowly reached out towards Luna's hand but stopped when she suddenly moved away a little bit. Luna turned towards the CPU candidate who looked down a little for some reason. "What's wrong?"

"Oh! It's nothing!"

"Oh, I see," Luna said as sat down on one of the benches. "So, are you having fun?"

"Yes! I am."

"That's good," Luna said as she looked off towards the nearby bush just in time to see Noire duck down to avoid being seen. But unfortunately for her, she did notice her, Luna smirked a little before turning her attention to the little sister CPU. "There's something I want to say."

"Okay, go ahead."

"You probably shouldn't like me with the way you do."

"What? Why?"

"I'm just not dating material."

"What makes you say that?"

"If you knew my past you would change your tone faster than you could fire your full automatic gun. I'm sure there's a nice guy, or girl in this case, who is really nice and cares about you out there. Is there?"

"Uh, y-yeah. Now that I think about." Uni said as the only person that came to mind was a certain lilac haired Candidate. "Besides, I can like or dislike whoever I want."

"That's true. I can't really change that." Luna said as she just shrugged a little before telling her some more bad news "So, I have some bad news. We're gonna have to end this date here."

"What? Why?"

"I just remember there's this important item that I have to look for. I need to find it as soon as possible."

"Oh, I see," Uni said feeling a little disappointed and upset that their date was ending.

"Don't look so disappointed, you'll make me feel bad about this. Look, I had a great time and, you know what? I'm always up for another."

"Really?"

"Yes, really. How about I give you something to show my appreciation..."

"Uh, okay? What is it?"

"I don't know, I was thinking of something like a... kiss?" Luna said loud enough so that Noire will hear what she said.

"A kiss!?" Both Uni and Noire said, although, it was more like shouting on Noire's part which seemed to catch the attention of the sister.

"Wait, that sounded like-" Before Uni could say anything else and to confirm who the voice belonged to, she felt a hand grab her chin forcing her to look at who it was. Uni blushed furiously and her heart started beating faster from the sudden lip contact from Luna, but she slowly started to enjoy it. After a few seconds, Luna released the CPU candidate who is trying to hide her embarrassment by looking away while Luna was smirking in amusement.

' _It's so fun messing with these two.'_ Luna thought as she left the CPU candidate by herself.

"I can't believe she did that!" Noire said to herself as she sitting down behind a bush not aware of the mage staring at her in amusement.

"So, how long you just gonna sit there?"

"Wah! How did you know I was here?!"

"I knew you were following us the whole time."

"You did?"

"Yep! So, tell me, what was it?"

"What do you mean?" Noire asked, genuinely confused about what she meant by that question.

"Did you follow us out of jealousy, or concern?"

"C-Concern! O-Obviously! You're not exactly the safest person to be around."

"I... won't argue with you there," Luna said before continuing onward. "Well, I'll see you sometime later."

"Where are you going?" Noire asked.

"I'm... off to go find something important," Luna said as she waved her hand and suddenly her staff appeared out of nowhere. The staff floated in front of Luna before floating down to the ground and she stepped on it before taking off to the skies with incredible speed.

* * *

 _ **Planeptune**_

Histoire floated into the room where Neptune was once again playing games instead of working which bugged her to no end. "Neptune," Histoire called out.

"Aw, damn it!" Neptune said as she lost at the game she was playing. "Yo, what's up?"

"Neptune! You haven't done any work since you got back from Lowee!"

"Yeah, I know. But there I haven't seen anything though."

"That's because you didn't even bother to look, or you ignored me!"

"I'm sorry."

"Look, there's something I want you to do."

"Oh? What is it?"

"There's a suspicious individual flying around Planeptune emitting a strange light. I want you to go investigate."

"Okay, might as well do it. It doesn't sound like it'll take that long." Neptune said as she stood up ready to take on this story job.


End file.
